I was trying to learn how to do shared preferences by making a simple app that just has a checkbox and saves when the program is closed and then send a toast when they are saved. I wanted it to reopen the preferences on onCreate. For some dumb reason I am absolutely and totally confused. I have written and rewritten code that I though was right and my program keeps crashing as soon as I push the button to go to the preference activity. I'm sorry if this is vague. I am so confused I don't even know what to ask! I would appreciate it so much if someone could help me! Thanks guys.